Diabetic foot case presentation

for anesthesia and medicine residents,
superb ppt starting with case and later discussion on diabetes and preoperative management

1. CASE PRESENTATION OF DIABETIC FOOT By: Dr. Gowri Shankar B Under the guidance of Dr. Trupti pethkar

2. History Pt. Abdul Sattar S/o Abdul Karim, 56 yrs. Muslim,. R/o Aroli admitted on 22/08/17 Chief complaints- # Pins and needle sensation × 1 year # nonhealing Ulcer on right foot post amputation × 1 month

3. History HOPI- Pins & needle sensation Left foot both feet ( Associated heaviness) Ulcer following trauma Papule pustule ulcer wet gangrene debridement and amputation of lateral four toes Discharge: yellow, foul smelling, blood stained No h/o fever with chills/cough / cold No h/s/o burning micturition / APD/loose stools

4. No h/o blurring of vision/altered color perception No h/s/o hypo/ hyperglycecmic episodes No h/o swelling of face or body. No h/o chest pain/ palpitations/ excertional breathlessness. No h/o fainting episodes/altered sensorium History

5. Past history K/c of type2 DM, Diagnosed 10 yrs back . Taking treatment for past 10 years OHG drugs and has stopped insulin from last 5-6 months. Underwent amputation of 2 nd to 5 th toes, 1months back under spinal anesthesia , uneventfull . No history of Tuberculosis, hypertension, asthma, paralysis, thyroid dysfunction was obtained. No history of furuncles or abscesses at other body parts was noted.

6. Drug history The patient was on Glybenclamide 10 mg OD for first 8 years of DM. For last 2 years he has been taking Glymeperide and Metformin combination (2.5/500 mg), BD . – non compliant stopped since 3 months. Gabapentine 400 mg /day was also taken on and off. Since hospitalization, he is on regular insulin 6-6-6 units. He is taking aspirin 75 mg HS for last two months.

7. Personal History The patient is a M uslim male, laborer by profession, he is non-vegetarian, non-alcoholic, non smoker. He is having frequency of urination around 15 per day including 3-4 times at night and constipation with frequency of once in three days. His appetite is normal but complains of losing the taste of the food he eats, and thus ensuing decreased intake and slow weight loss for past few years.

8. General physical Examination The patient at time of examination was conscious, co-operative and oriented to time place and person. He was lying comfortably supine with right leg resting slightly abducted and flexed at knee on a pillow. General built of the patient is cachexic . Normal age related graying of hair and frowning of forehead seen. Pallor-, Icterus -, clubbing -,cyanosis - , edema + Right inguinal lymph nodes - 3×2 cm in size discrete, firm, mobile, non tender, non –erythematous.

9. VITALS PR - 84 / min (right radial ). Regular rhythm with normal pulse volume . All peripheral pulses palpable including dorsalis pedis on affected side, No radio-femoral delay BP – 128/86 mm Hg right brachial in supine position and 102/76 mm Hg on standing Temperature afebrile RR – Thoraco-abdomional , rate 16/min, no accessory muscles being used. General physical Examination

10. Airway Mouth opening – >2fingers Modified mallampatti score - I Thyro mental distance - >3fingers Hyomental disatance > 3 fingers Dentition – normal , no caps or dentures Prayers sign - negative. Palm print test – not done. General physical Examination

11. Local examination-Ulcer Inspection - Single large irregular ulcer, 7-8 cm in size, extending from base of amputated stump of 2nd metatarsal to 5th metatarsal, inflamed, edematous, sloping edge, red floor with granulation tissue. Palpation - Tender, sloping edges with irregular margins, indurated base, depth 3mm, bleeding on touch, mobile, warm surrounding skin , peripheral pulses palpable.( dorsalis pedis and posterior tibial )

12. Systemic examination CVS – S1 S 2 heard, no murmurs. RS- b/l AEE, no added sounds. P/A- soft , bowel sounds present. CNS- HMF normal, NFND .

13. Provisional diagnosis 50yr male known type 2 diabetic on irregular treatment with associated peripheral neuropathy presenting with non healing amputated stump ulcer on right foot for debridement.

14. Investigations Hb - 8.1mg/dl FBS- 142mg/dl, PP BS- 220 mg/dl Blood urea- 97 mg/dl S creatinine- 3.1 mg/dl Na+ : 130 meq /l K+ : 3.7meq/l Cl - : 104meq/l ECG-TWNL X-ray Chest- NAD Xray cervical spine- NAD Fundus examination -

15. Discussion

16. Diabetes mellitus (WHO) - A metabolic disorder of multiple etiology characterized by chronic hyperglycemia with disturbances of carbohydrate, fat and protein metabolism resulting from defects in insulin secretion, insulin action or both .

17. DM in India INDIA : Diabetic CAPITAL of the world 4 crore diabetics in India (19% of world’s diabetic population) 2.5% of India’s urban population is diabetic DIABETIC FOOT is most devastating with > 50,000 leg amputations/ every yr. due to D.M. in India

18. Criteria for Diagnosis of DM Adapted from American Diabetes Association 2013

19. Relation between whole blood and plasma glucose Blood glucose + 15 % = Plasma glucose 1 m mol = 18.0 mg glucose 1 m mol /l = 18.0 mg glucose/dl Relation ship between arterial/capillary/ venous arterial=capillary =7%> venous

20. What Factors Affect the Perioperative Anesthetic Management of DM ? Type, duration of DM Medication (OHA, insulin) Level of glycemic control End-organ damage, particularly autonomic dysfunction Nature of surgery - major - minor Urgency of surgery Need for critical care •

21. Oral hypoglycemic agents Sulfonylureas – Long acting discontinued 48-72 hours before surgery, Short acting held night before or morning of surgery Thiazolidinediones : Rosiglitazone, piaglitazone omitted on morning of Sx Biguanides : Metformin discontinued atleast 24 h prior to Sx & held for 48 h after major Sx Alpha- glucosidase inhibitors ( acarbose , miglitol ) have no effect on fasting blood glucose

22. Action of Antidiabetic Agents

23. Insulin Preparations

24. ?????? But why regular treatment ? What is glycemic control? HBA1C? C omplications

25. Classical diabetic complications Nephropathy Peripheral neuropathy Retinopathy IHD, CHF & cardiomyopathy Autonomic neuropathy Stiff joint syndrome Electrolyte & metabolic derangement Microvascular Complications Macrovascular Complications

26. To Assess Glycemic Control History and Examination - Hyper/ hypoglycemic episodes - Medication & compliance Investigations - BS (fasting, PP) - GTT (if required) - Glycosylated Hb (HbA1C)

27. Erythrocyte haemoglobin is non - enzymatically gylcosylated by glucose that freely crosses RBC memb Gives BG control in preceding 60 to 90 days Normal range is 4%-6% HbA1C >6.5% -↑ ed risk of micro & macrovascular disease Glycated Haemoglobin (HbA1c ) Strict glycemic control can delay onset & slow progression of microvascular complications

28. Glycemic Control IDF Clinical Guidelines Task Force 2005

29. Nephropathy Peripheral neuropathy Retinopathy Microvascular Complications- how to assess?

30. Microalbuminuria earliest lab manifestation of diabetic nepropathy . HT most imp factor responsible for progression of diabetic renal disease; hyperglycemia , hypercholesterolemia others ACE inhibitors: ↓albuminuria & progression of renal dysfunction nephropathy Renal system- nephropathy

31. To Assess Nephropathy • History and Examination - H/o swelling of face and body - H/o hypertension and its medication • Investigations - Urine: proteins, sugar - Microalbuminuria on a timed overnight collection - B. urea, S. creatinine, S. electrolytes

32. More chances of ARF( 7 %), most common major complication in perioperative period, due to - Intrinsic renal disease. - Hemodynamic impairment - Urosepsis UTI-most common post op complication in diabetics undergoing surgery Adequate renal perfusion, avoiding nephrotoxins , hemodynamic monitoring ↓risk of postop renal dysfunction Renal system- nephropathy

33. To assess Peripheral Neuropathy • History and Examination - Foot ulcers - Paresthesias , dysthesias , neuropathic pain Sensorimotor loss appears in toes or feet & progresses proximally in a "stocking and glove" distribution • Investigations - Loss of light touch, propioception , pain, temperature

34. To Assess Retinopathy • History and Examination - Vision deterioration - Changes in color vision • Investigation Ophthalmologic examination- fundus

35. IHD, CAD, CHF & cardiomyopathy Autonomic neuropathy Stiff joint syndrome Macrovascular Complications

36. Cardiovascular system Premature atheroma formation Chances of CAD (Male-double risk ; female-triple) Incidence of silent MI HT (29-54%) and its sequelae Cardiac dysautonomia may present with : Sudden hypotension on induction Absence of tachy . and HT with intubation Diabetic cardiomyopathy

37. To Assess Ischemic Heart Disease, CHF & Cardiomyopathy • History and Examination - Angina or MI - Breathlessness - Poor exercise tolerance - Edema feet, enlarged liver, raised JVP, basal crepts , S3/S4 • Investigations - ECG - X-ray Chest - Echocardiography

38. Preoperative Cardiovascular Screening • Asymptomatic diabetic pt who has some or all risk factors such as advanced age, smoking, hyperlipidemia & HT • Stress testing should be considered in patients with multiple cardiac risk factors & poor or indeterminate exercise tolerance • Those with high risk diabetics, ‘metabolic syndrome’, undergoing major elective non‐cardiac surgery

39. Respiratory system • More chances of resp tract infections • ↓ ventilatory response to PaCO2 & PaO2 • ↑ susceptibility to ventilatory depressant drugs • ↓ FVC & FEV (glycosylation of tissue proteins), ↓ lung diffusing capacity • ↓ 2,3 DPG → ↓ release of O2 to tissues • DM affects O2 transport by causing glucose to covalently bind to Hb & alters allosteric interactions b/w β chains

40. Neuropathy Changes in the vasonervorum with resulting ischemia ? cause Increased sorbitol in feeding vessels block flow and causes nerve ischemia Intraneural acculmulation of advanced products of glycosylation Abnormalities of all three neurologic systems contribute to ulceration

41. Autonomic Neuropathy Autonomic system regulates sweating and perfusion to the limb Loss of autonomic control inhibits thermoregulatory function and sweating Result is dry, scaly and stiff skin that is prone to cracking and allows a portal of entry for bacteria leading to ulcer.

42. www.plymouthdiabetes.org.uk/

43. Ulcer Classification Wagner’s Classification 0 – Intact skin (impending ulcer) 1 – Superficial 2 – Deep to tendon, bone or ligament 3- Osteomyelitis 4 – Gangrene of toes or forefoot 5 – Gangrene of entire foot

44. To Assess Autonomic Neuropathy (DAN) History and Examination - Early satiety, hypoglycemia unawareness - Lack of sweating - Gastroparesis in form of nausea, vomiting, bloating, reflux nocturnal diarrhea , constipation, abdominal distension - Postural syncope (orthostatic hypotension) - Bladder atony & urinary retention - Impotence/erectile dysfunction, retrograde ejaculation - Palpitations, Irregular pulse - Sensory discomfort of lower limbs

45. www.plymouthdiabetes.org.uk/

46. Investigations • Tests for parasympathetic control - HRV Resting tachycardia : > 100 beats/min is abnormal Beat-to-beat variation with deep breathing obtunded : max HR-min HR at 6 breaths per min, < 5bpm, N >15 bpm, Normal R-R inspiration/R-R expiration > 1.17 HR response to standing obtunded : ratio of longest R-R around 30 th beat after standing to the shortest R-R around 15th beat after standing (N > 1.04 ) - HR response to Valsalva maneuver obtunded : the normal ratio of longest R-R to shortest R-R > 1.21

47. Tests for sympathetic control - BP response - SBP response to standing : BP(lying) - BP(standing) >30 mm Hg (N<10 mmHg) - DBP response to sustained handgrip : handgrip sustained at 30% of maximum squeeze for up to 5 minute & BP every minute, DBP just before release – initial DBP (N > 16 mmHg) - BP response to Valsalva maneuver obtunded Investigations for DAN

48. DAN Scoring

49. DAN Scoring Bellavere F et al. Br Med J (Clin Res Ed) 1983;287:61

50. To Assess Stiff Joint Syndrome Prayer Sign”- inability to approximate the palmar surfaces of phalangeal joints despite max effort - “Palm print test” - Degree of interphalangeal joint involvement assessed by scoring the ink impression made by palm of dominant hand - Non-familial short stature Tight-waxy skin • Investigations - X-ray CS to delineate limited atlanto -axial extension

51. Palm Print Test Grade 0 - All phalangeal areas visible Grade 1 - Deficiency in the interphalangeal areas of 4th &/or 5th digit Grade 2 - Deficiency in the interphalangeal areas of 2nd to 5th digit Grade 3 - Only tips of digits seen

52. A Positive "Prayer Sign"

53. To Assess Electrolyte & Metabolic Derangements • History and Examination - Non-compliance of drug - Severe infection or starvation - Poor control in the past few days/weeks S/S of hypoglycemia or ketoacidosis • Investigations - ABG & electrolytes

54. Acute metabolic Effects of Hyperglycemia • Dehydration - osmotic diuretic effect of glycosuria • Acidemia - accumulation of lactic &/or ketoacids • Dyselectrolemia - hypophosphatemia • Hyperviscosity with ↑ ed thromogenic complications • Exacerbation of brain, SC & renal ischemic damage • Impaired immune system response → postop infection ↑ • Impaired consciousness “Permissive Hyperglycemia ” Unacceptable

55. Clinical Significance • Impaired host response to infection → aseptic precautions • Decreased mobility in TM, atlanto -occipital joint & cervical spine – restricted neck movements & difficult laryngoscopy • Proliferative retinopathy - vitreous H’ge on laryngoscopy & intubation • CAD & IHD - myocardial ischemia • Hypertension - pressor response to L&I, poor intraoperative BP control, cerebrovascular infarction

56. Autonomic neuropathy • ↓compensatory cardiovascular response - IPPV, bld loss, position change, drugs , SA > hypotension • Blunted response to atropine • Full stomach - risk of aspiration, longer preop fasting, RSI • Impaired ventilatory responses to hypoxia, hypercarbia – resp arrest • Increased risk of dysrhythmias due to loss of HRV • Urinary stasis - unnecessary bladder catheterization • Loss of signs of hypoglycemia • Hypothermia - increased risk intraoperatively Clinical Significance

57. Neuropathy & vascular compromise: - ↑ risk for ischemia in pressure points while shifting & positioning (heel ulceration) - ↑ incidence of nerve injury & ischemia implications for RA • Renal disease - impaired drug excretion, renal ischemia, more likely to develop postoperative renal failure • Associated complications - DKA/NKHC - hypoglycemia Clinical Significance

58. Diabetes & Accelerated Physiologic Aging • Adverse perioperative outcomes repeatedly & substantially correlated with age of patient • Type 1 diabetic with poor control of BS ages approx 1.75 yrs physiologically for every chronologic yr of disease, 1.25 years if BS controlled tightly • Type 2 diabetic ages about 1.5 yrs for every chronologic yr of disease, 1.06 yrs with tight control of BS & BP

59. Does DM Increase Perioperative Risk? • Yes, average diabetic pt presents a higher perioperative risk than average non-diabetic pt • Common postoperative complications - delayed wound healing, sepsis, urinary retention & infection, angina, MI, hypotension/HT, episodes of hyper or hypoglycemia , DKA Increased Morbidity & Mortality Intensive Monitoring Longer Hospital Stay

60. Perioperative Problems in Diabetic Patient • Surgical induction of stress response with catabolic hormone secretion →anti‐insulin effect → insulin requirements in this period unpredictable • Surgery associated with a reduction in insulin sensitivity • Interruption of food intake, esp after GI procedures • Altered consciousness, which masks sx of hypoglycemia • Circulatory disturbances associated with anaesthesia & surgery, which alters absorption of subcutaneous insulin

61. Diagnostic Tests For Cardiovascular Autonomic Neuropathy Resting heart rate > 100 beats/minute is abnormal Beat-to-beat heart rate variation The patient should abstain from drinking coffee overnight Test should not be performed after overnight hypoglycemic episodes When the patient lies supine and breathes 6 times per minute, a difference in heart rate of less than 10 beats/minute is abnormal Heart rate response to standing The R-R interval is measured at beats 15 and 30 after the patient stands A 30:15 ratio of less than 1.03 is abnormal Heart rate response to Valsalva maneuver The patient forcibly exhales into the mouthpiece of a manometer, exerting a pressure of 40 mm Hg, for 15 seconds A ratio of longest to shortest R-R interval is the valsalva ratio less than 1.2 is abnormal

62. Systolic blood pressure response to standing Systolic blood pressure is measured when the patient is lying down and 2 minutes after the patient stands A fall of more than 30 mm Hg is abnormal A fall of 10 to 29 mm Hg is borderline Diastolic blood pressure response to isometric exercise The patient maintains a handgrip of 30%of maximum handgrip squeeze for 5 minutes. BP is measured every minute Initial DBP is subtracted from the DBP just before release Difference of more than 16 mm Hg is normal

63. Treatment Control of diabetes Education Ambulation Shoe ware Skin and nail care Avoiding injury with F.B’s and Hot water Local padding and dressing Antibiotics if infected Excision of infected bone Amputation

64. Anaesthetic considerations

65. Anaesthetic Technique & the Diabetic Patient • Anaesthetic techniques (GA/RA or N blockade) may modulate secretion of catabolic hormones & any residual insulin secretion • Perioperative increase in epinephrine & cortisol conc in pts under GA is blocked by EA → much less disruption of glucose metabolism • Induction agents affect glucose homeostasis perioperatively -> clinically not significant

66. Anaesthetic Agents & DM • Etomidate blocks adrenal steroidogenesis → cortisol syn • ↓ hyperglycemic response to surgery by approx 1mmol/L • Benzodiazepines in high doses - ↓secretion of ACTH → ↓ production of cortisol ↓ sympathetic stimulation→↓in glycemic response • High‐dose opiate techniques block SNS & hypothalamic-pituitary axis → abolish hyperglycemia • Halothane, enflurane , isoflurane inhibit insulin response to glucose in a reversible & dose‐dependent manner

67. Anaesthetic management goals 1 To maintain glycaemic control 2 To avoid further deterioration of pre-existing end organ damage 3 To shift patient soon on pre op glycaemic control - drugs

68. Preoperative assessment -Aims 23% of diabetics diagnosed prior to surgery Type of DM & its duration Pre op evaluation and treatment of end organ damage which is responsible for 5-fold increase in perioperative mortality associated with D.M. Assessment of B. sugar control and to obtain a reasonable control with change to short acting drugs Limit hospital stay and decrease cost Quantification of risk

69. PAC To assess Investigations 1 B sugar BS- F &PP Control Hb1 A C 2 Nephropathy Urine R/M, albumin microalbuminuria Kidney function tests

70. PAC To assess Investigations 3 Cardiac ECG status Chest X ray ECHO 4 PVD H/o intermittent claudication Blanching of feet Non healing ulcers 5 Retinopathy Fundus exam

71. PAC To assess Investigations 6 Stiff joint X ray Cervical spine syndrome (lateral) 7 Metabolic & ABG electrolyte S electrolytes Ketones-urine 8 ANS HR variability Postural changes in BP

72. Aims of Peri -operative Glucose Management • Avoid hypoglycaemia ( intraop BG 120-180mg/dl) • Minimize hyperglycemia • Avoid loss of electrolytes (potassium, magnesium & phosphate) • Prevent lipolysis & proteolysis • All patients with diabetes treated with insulin should be managed same way, irrespective of whether they have type 1 or type 2 DM

73. Preoperative Orders • 1st on list • Last dose of long acting sulfonylureas chlorpropamide ) on morning of day before surgery • OHA/insulin to continue till night prior to surgery • NPO for 12 hrs preop • On morning of surgery, omit OHA/normal SC insulin • Investigations - FBS, serum electrolytes morning of surgery

74. • Gastric prokinetic agent + H2 blocker • Sedation & anxiolysis , other medications (anti- hypertensives ) continued • IV line - GI infusion started on morning of surgery after taking sample for fasting BS • To arrange for dextrostix, insulin, glucometer etc Preoperative Orders

75. Peri-operative complications with Hyperglycemia Dehydration, electrolyte & metabolic disturbances Predisposes to DKA Delayed wound healing Bacterial infection & post-op wound infection Median glycemic threshold for neutrophil dysfunction 200 mg/dl Worsens clinical outcome in stroke, traumatic brain injury, global & focal cerebral ischemia

76. How Do You Manage the Insulin & Glucose Requirements on Day of Surgery? • No glucose no insulin regimen NOT recommended • Glucose to prevent hypoglycemia , periop glucose enhances postop glucose utilization rates • Insulin to prevent hyperglycemia , lipolysis & proteolysis • 1 gm of glucose neutralized by 0.32 U of insulin, 500ml 5%D = 25gms = 8 U

77. Intraoperative glucose control Subcut insulin not advised – potentially erratic absorption secondary to altered regional blood flow, tissue edema, or fluid shifts during Sx Iv bolus of insulin : very short half life (8 min), dangerous iatrogenic hypokalemia, hypophosphatemia, hypomagnesimia, hypoglycemia Iv insulin infusion preferred Adsorption of onto surface of syringes, iv fluid bags & iv sets - unavoidable problem. Flush line & discard - saturates insulin binding sites of tubing

78. Factors considered in selecting a regimen for glycemic control Type of DM and treatment How aggressively eu-glycemia sought Whether patient takes insulin Surgery minor & in an ambulatory unit Surgery elective or emergency Ability of hospital resources

79. Patients on Diet Alone • For pts maintained on diet alone & well controlled (HbA1c < 6.5%), no specific therapy required, more frequent BG monitoring recommended ( during procedure check hrly ) • BG remains above 10 mmol /L (180mg/dl) in pre/perioperative period, an IG infusion should be started & continued until they resume eating • If starvation period is short, (only one missed meal) no insulin, if omission of more than one meal, insulin +glucose reqd • If pt does not become hyperglycemic following surgery, monitor BG every 4-6 hrs until resumption of usual meals * Perioperative Diabetes Management Guidelines - Australian Diabetes Society May 20012

80. Patients on OHAs alone • Change to insulin or no - for minor surgery → accept as such - for intermediate surgery - if well controlled – accept - if not well controlled – change - for major surgery → change to insulin • Omit on the day of surgery • Restart medication when patients are able to resume normal meals • Commence an IG infusion peri -operatively Perioperative Diabetes Management Guidelines - Australian Diabetes Society May 20012

81. Classification of Surgeries Minor surgery is defined as all day-only procedures, while major surgery includes all procedures that require at least an overnight admission

82. The Vellore Regimen • On day of surgery, OHA & insulin omitted, all pts BG measured at 6 AM • Insulin 5 U in 500 mL 5%D started in ward at 8 AM using measured volume set,@ 100 mL/ hr • Intraop BG control with 1 U of insulin for every 1–50 mg of BG value > 100 mg/ dL added to 100 mL of 5% D in a measured volume set • Hrly monitoring of BG, BG measurements till pts leave PACU • Simple & effective method , combines advantages of combined glucose insulin & variable rate insulin infusion

83. Most operative pts can be maintained in 120-180 mg/ dL range with insulin infusion rate 1 - 2 U/h • Serum potassium measured during major abdominal surgery, supplementation given if levels < 3.5 mEq /L

84. Dextrose Insulin Infusion • Intraoperative serum glucose levels should be maintained between 120 and 180 mg/ dL • 1 unit insulin lowers BG 25-30mg/ dL • Initial hrly rate for continuous insulin infusion = total daily insulin reqm /24 • Typical rate 0.02 U/Kg/ hr or 1.4 U/ hr in 70-Kg patient • Insulin infusion prepared by mixing 100 U regular insulin in 100 mL NS (1 U/mL)

85. Insulin infusion accompanied by an infusion of 5% D in half-NS with 20 mEq/L KCl at 100-150 mL/hr • Insulin infusion requirements higher for - CABG surgery - solid organ transplant - pts receiving steroids - pts with severe infection - pts receiving hyperalimentation - pts on vasopressor infusions • Algorithm 1 : Start for most patients

86. Inpatient Insulin Algorithm Stoelting's Anesthesia And Co-existing Disease

87. • Algorithm 2 : Start if pt requires higher insulin or receiving >80 U/d insulin as outpatient • Moving up : algorithm failure defined as BG outside goal range for 2 hrs & level does not change by at least 60 mg/ dL within 1 hr • Moving down : When BG is < 70 mg/ dL for two checks OR if BG decreases by > 100 mg/ dL in an hour • Pt monitoring : Check BG every hr until it is within goal range for 4 hr , then every 2 hr for 4 hr , & if it remains at goal, may ↓ to every 4 hr

88. Postoperatively • Recommence OHA - 1/2 dose with first meal - full dose next day • Recommence normal SC insulin with first meal • Major surgery - continue insulin infusion till regular diet - regular insulin once pt starts orally • Avoid metformin in hepatic or renal insufficiency or CHF • Inadequate pain relief ↑ es catabolic hormone secretion • Hyperglycemia detected postop in pts not previously known to have DM should be managed as if DM present & diagnosis reconsidered once pt has recovered.

89. Tight control regimen Aim : 79-120 mg/dl Protocol Evening before, do pre-prandial blood glucose Begin iv 5%D @ 50 ml/ hr /70 kg Piggyback to 5%D, infusion of regular insulin (50 U in 250 ml 0.9% NS) Insulin infusion rate (U/ hr )  plasma glucose (mg/dl) / 150 or /100 if on steroids or severe infection Repeat blood glucose every 4 hours Day of surgery : Non dextrose containing solutions, Monitor blood glucose at start & every 1-2 hours

90. Sliding scale glucose insulin 150 – 200 mg/dl 2 U regular insulin 201 – 250 mg/dl 4 U 251 – 300 mg/dl 6 U 301 –350 mg/dl 8 U >350 mg/dl 10 U

91. GENERAL VS Regional anaesthesia

92. Regional anaesthesia No absolute indication for spinal or epidural anesthesia May improve outcome in selected situations Extend analgesia into postoperative period

93. Advantages of regional anaesthesia in diabetics Awake pt , intraop hypoglycemia (early recognition of hypoglycemia) can be noticed Risk of aspiration, PONV chances Blunt stress response to surgical stimulation Avoidance of endotracheal intubation { stiff joint syndrome & Gastroparesis } Metabolic effects of anaesthetic agents avoided

94. Advantages of regional anaesthesia in diabetics Lower the incidence of postoperative thromboembolic events Decrease intraoperative blood loss Insulin response to hyperglycemia • high thoracic (T1-T6) blockade > inhibited • low blockade (T9 - T12) > no effect Epidural anaesthesia block catecholamine release irrespective of the segmental level R apid return to diet and insulin/ OHA

95. Disadvantages of Regional Anaesthesia in Diabetic patients Risk of nerve injuries, higher adrenaline use increases risk of ischemic injury LA requirement is low - sensitivity Risk of infection Epidural abscess Contraindicated in presence of peripheral neuropathy

96. PRECAUTIONS Document peripheral neuropathy • Relative contraindication • Keeps patients & relatives informed • Avoids medico-legal issues later on • Pt with autonomic neuropathy - profound Hypotension may occur with deleterious consequences in a pt with co‐existing CAD, cerebrovascular or renovascular disease • Use of continuous techniques DOES NOT predispose pt to persistent neuropathy after surgery* Anesth Analg 2003; 96:247-52

97. General Anaesthesia Should be considered in -Presence of cardiovascular or renal disease -Prevention of intraoperative hypoglycemia and hypotension -Autonomic neuropathy -Protection of pressure sores

98. General Anaesthesia Anaesthesia - if gastric stasis a rapid sequence induction should be used. A nasogastric tube can be used to empty the stomach and allow a safer awakening. Treat hypotension promptly. Hartmanns solution (Ringers lactate) should not be used in diabetic patients as the lactate it contains may be converted to glucose by the liver and cause hyperglycaemia .

99. General Anaesthesia IV induction agents normally cause hypotension on injection due to vasodilatation. If a patient has a damaged autonomic nervous system (and many diabetics do), then they cannot compensate by vasoconstricting , and the hypotension is worsened. Reducing the dose of drug and giving it slowly helps to minimise this effect. Sudden bradycardias should respond to atropine 0.3mg iv, repeated as necessary (maximum 2 mg). Tachycardias , if not due to light anaesthesia or pain, may respond to gentle massage on one side of the neck over the carotid artery. If not then consider a beta-blocker

100. Stress response and glucose metabolism Glucagon, epinephrine, GH, steroids, Insulin Insulin resistance in post operative period Consequences - Osmolar diuresis-dehydration -disrupts autoregulation of vascular beds -impaired wound healing -decreased chemotaxis and impaired phagocytosis -more acute complications

101. Diabetes & Emergency Surgery Usually infected Usually uncontrolled Dehydration Metabolic decompensation Resistance to insulin

102. Special Scenario: Urgent and Emergency Surgery Check blood glucose <250 mg / dl, iv insulin – glucose, delay surgery till hydrated and electrolytes corrected >250 mg /dl, check ketones, arterial blood gas, anion gap. If DKA present Large volume of normal saline iv Regular insulin 0.1U/ Kg/h after initial bolus of 0.15 U/Kg. Blood glucose monitoring 1 hourly Potassium, magnesium and phosphate monitored 2 hourly and replaced accordingly Blood glucose < 250 g/dl start 5% dextrose with insulin. Once acidosis corrected, blood glucose < 200 mg/dl, patient may be taken for surgery 104

103. Postoperative Complications Hypoglycemia Hyperglycemia – DKA, NKHC Infections Delayed wound healing Periop MI risk watch till 72 hrs Problems due to autonomic neuropathy, postural hypotension, atonic bleeding, urinary retention PONV Pain

104. Hypoglycemia Most frequent and dangerous complication of Insulin therapy Exacerbated by simultaneous administration of alcohol, OHA, ACE inhibitors, MAO inhibitors, and nonselective beta blockers Plasma glucose level less than 50 mg/ dL If unconscious: 50 ml of 50% dextrose (D50) which increases glucose 100 mg/ dLor 2 mg/ dL /mL Insulin

105. questions RL / bank blood Adsorption of insulin, Older rgimens Intraop -Hypo/hyperglycemia Emergencies- DKA DKS vs NKHC Shift To Insulin ?? Surgery classsification

106. Thanks..!

107. RL / bank blood • Lactate is a gluconeogenic substrate, RL = 28 mEq /L • Bank blood = variable amounts (anaerobic metabolism during storage) • Hepatic conversion to glucose → hyperglycemia aggravated • Rapid infusion of RL↑ BG by no more than 1 mmol /L • RL/blood NOT contraindicated but inappropriate as these can confound calculation of glucose load & insulin requirements somewhat

108. Shift To Insulin ?? • No - Well-controlled type 2 DM (on OHA), minor surgery • Yes - Poorly controlled type 2 DM - Well-controlled type 2 DM for major surgery - Type 1 DM having minor surgery or major surgery • Switch to combination of short & intermediate acting insulin • Diet controlled type 2 DM - treat as non-diabetic, Monitor, before surgery, hourly, treat if increased

109. Adsorption of Insulin • Significant amounts of insulin adsorbed on to giving sets: high‐volume, low‐insulin conc regimen used • Reducing initial rates of insulin delivery • In sol with conc of insulin of ∼10U/L, effect is minimal • Strategies to minimize - use concentrated solutions - use smaller containers - use shorter tubings - prime tubing with insulinized sol - add whole blood/human albumin

110. Hyperglycemia Intraoperatively ?? • Intraoperative hyperglycemia - BG level >250 mg/ dL • Each unit of regular insulin ↓ es BG by approx 30 mg/ dL • Increase infusion rate, small doses as single IV bolus • BG monitored frequently to dictate further therapy

111. Hypoglycemia • Plasma glucose level less than 50mg/ dL • Exacerbated by simultaneous administration of alcohol, OHA, ACE inhibitors, MAO inhibitors, nonselective β blockers, in poorly controlled pts , liver disease , fasting, sepsis, equipment failure Awake patient • Adrenergic symptoms : sweating, tachycardia, pallor, palpitations, restlessness • Neuroglycopenic : fatigue, confusion, headache, incomprehensible speech, somnolence , convulsions, coma

112. Under GA - initially sx of sympathetic stimulation: sweating, tachycardia, hypertension , &/or dilated pupils • Clinically significant hypoglycemia defined by Whipple’s triad: symptoms of neuroglycopenia , BG conc <40 mg/ dL & relief of symptoms with glucose • Treatment - if conscious → oral glucose (sugar cube, juice ) - if unconscious →  25ml of 50%D IV (↑ BG level 100 mg/dl)  glucagon 0.5-1.0 mg IV/IM/SC Hypoglycemia

113. Start aggressive treatment of DKA • Aims: - Rehydration (water and salt)→ reestablish U/O - Lower blood sugar - Correction of potassium depletion • Partial correction of hyperglycemia, metabolic acidosis & ketosis • Start treatment of infectious process (antibiotics), if present

114. Treatment of DKA • Volume resuscitation - start an IV infusion of 0.9 % NS as -1 litre over 30 min - then 1 litre over 1 hr - then 1 litre over 2 hrs • Continue 2-4 hrly until BG below 250mg/ dL , then add 5% D to IV fluids, then 0.45% NS @ 250ml/ hr • Use BP, HR, CVP, conscious level to judge fluid amount • Insulin - 50U in 50ml 0.9% NS, at a fixed r/o 0.1 / kg/ hr , i.e. 7ml/ hr in 70kg pt - called fixed rate IVII • Max r/o ↓ in BG fairly constant -75 to 100 mg/ dL / hr

115. Why Avoid Precipitous Falls in Blood Glucose ?? • Extreme hyperglycemia - brain accumulates idiogenic osmoles ( glucose, polyols , free amino acids) to prevent cerebral osmotic dehydration • As the movement of these osmoles across BBB is very slow relative to water , hence • Rapid reduction in BG leaves brain hyperosmolar relative to plasma development of osmotic cerebral edema

116. K+ deficits range from 3 -10 mEq /Kg, nadir? • High blood K+ initially, falls as BG level ↓, measure hrly • Put 10mEq K+ in 1st litre of NS, then 10-40 mEq per litre subsequently, depending on K+ level (<5.5mEq/L ) • If K+ measurements unavailable, put 10mEq KCl in each litre of fluid, if low K + levels initially, delay insulin • Other measures -100 % O2, consider HCO3 if pH<7.0, bicarb conc < 10mEq/L , hypotension unresponsive to IV fluids

117. Resolved !!! The guidelines from American Diabetes Association (ADA) consider DKA resolved when • Blood glucose < 200 mg/dl • Bicarbonate is ≥ 18 mEq /L • Venous pH is > 7.3 • Calculated anion gap ≤ 12 mEq /L The criteria for resolution of HHS include • Improvement of mental status • Blood glucose <300 mg/ dL • Serum osmolality of <320 mOsm /kg

118. Areas of Controversy • Can you measure venous rather than arterial HCO3 & pH - ? • Best practice in monitoring response to treatment -? • Is fluid resuscitation with colloid better -?

119. Is a priming dose (bolus) of insulin reqd – ? • Is intravenous phosphate reqd - ? • No evidence of benefit of phosphate replacement & routinely not recommended • If respiratory, skeletal ms weakness, ↓ myo contractility or level ↓ below 1.0 mg/ dL , replacement shd be considered Areas of Controversy

120. Diabetic Ketoacidosis (DKA) vs. Hyperglycemic Nonketotic Coma (HNKC)

121. Essentials Of Diagnosis DKA BG > 250 mg/dl • pHa < 7.3 • HCO3 < 15mEq/L • Anion gap > 12 • Moderate/severe ketonemia • Moderate/severe ketonuria • S.osmolarity <310 mOsm /L HNKC • BG > 600 mg/dl • pHa > 7.3 • HCO3 > 15mEq/L • Normal anion gap • Absent/minimal ketonemia • Urinary ketones -/minimal • Osmolality > 320 mOsm /kg • S.osmolarity >350 mOsm /L